Report presenting a blade-vibration and rotating-stall survey on a modified version of a production turbojet engine with a 13-stage axial-flow compressor with a design pressure ratio of 7 and an air flow of 120 pounds per second. This testing was carried out due to the problems rotating stall can cause with both experimental and production axial-flow compressors. Results regarding the rotating-stall patterns, rotor-blade vibrations, radial and axial strength of rotating stall, and maximum rotating-stall speed are provided.

The stage performance of the X24C-2 axial-flow compressor, as determined from radial distributions of total pressure and temperature measured in each stator-blade row, was investigated at design speed at weight flows corresponding to those of the maximum weight-flow, peak-efficiency, and surge points. The stage performance is presented as the measured stage pressure ratios and the calculated velocity diagrams. The average stage total-pressure ratio at the surge operating condition in the first stage was approximately 1.10; in the second stage, approximately 1.13; and in all remaining stages, approximately constant at a value of 1.15. Regions of inefficient flow are discussed so as to point out the reasons for the poor flow conditions.

Report presenting the effects of variation of trailing-edge angle and trailing-edge thickness on the lift characteristics of a 10-percent-chord thick symmetrical NACA airfoil section with a 25-percent-chord plain flap as determined from wind tunnel tests over a range of Mach numbers. Results regarding the section lift and pitching-moment characteristics, variation of lift coefficient with flap deflection, schileren photographs, and effect of angle of attack are provided.

Memorandum presenting an investigation of a 2:1 area ratio conical diffuser of length equal to the inlet diameter with separate variation of several basic parameters for simple nontwisted counterrotating rectangular vortex generators over a considerable range of inlet-boundary-layer thickness. The maximum values of static-pressure rise were determined for angle of attack, spacing, aspect ratio, and span-to-inlet boundary-layer thickness. Results for the diffuser with no vortex generators, effects of selectable vortex-generator variables, effect of inlet-boundary-layer displacement thickness, and use of the maximum indicated vortex-generator design values are provided.

Memorandum presenting flutter tests of untapered, low-aspect-ratio, sweptback-wing models and of triangular-wing models of solid magnesium, aluminum, and steel construction in an intermittent supersonic wind tunnel at Mach number 1.3. Flutter data are presented for 31 sweptback wing models and 24 triangular-wing models. The flutter boundaries are indicated on plots of streamwise thickness ratio and aspect ratio.

The effects of fineness ratio (14.2 and 12.2) and boattailing on aerodynamic characteristics of four bodies of revolution at Mach numbers from 1.50 to 1.99 within a range of angles of attack from 0 degrees 10 degrees at an approximate Reynolds number of 35x10(superscript)6 based on body length were investigated. A comparison of experimental data with available theory is included. At zero angle of attack, fineness ratio has no appreciable effect on model characteristics while boattailing and boattail convergence significantly affect fore drag and base drag.

The factors affecting the performance of ejector suitable for aircraft cooling are investigated theoretically and experimentally. The investigation covers a range of shroud-to-nozzle diameter ratios from 1.1 to 1.6, of shroud lengths from 0.2 to 2.28 nozzle diameters, of secondary-to-primary weight-flow ratios from 0 to 0.12, and of ambient-to-nozzle pressure ratios from 0.7 to 0.06. The results of a simplified theoretical analysis based on each type of flow are in good agreement with those experimentally obtained.

Report presenting combustion-efficiency data for a 5-inch ramjet-type combustor using a simple V-gutter flame holder. Data for homogeneous fuel-air mixtures of 14 pure fuels and 3 fuel blends cover a range of inlet static pressures and velocities.

Report presenting an evaluation of a 1/4-sector of an annular combustor designed for use with pentaborane fuel at a simulated altitude condition. Results regarding the pentaborane performance, combustor development, and the JP-5 fuel performance are provided.

Report presenting the effect of adjusting compressor inlet-guide-vane angle on overall compressor performance, stage performance, engine thrust, and specific fuel consumption in a 7000-pound-thrust turbojet engine. Data was obtained at several angles and demonstrated that increasing the guide-vane angle decreased the weight flow at the higher compressor speeds. It had no effect on stage performance other than at the first stage, where it reduced maximum flow, pressure, and temperature coefficients.

Report presenting a J47-25 engine instrumented with thermocouples and operated under steady-state and transient-conditions in an altitude test stand to determine the operating temperatures at altitude in the turbine section of a turbojet engine. Results regarding the temperature effects and transient operation are provided.

Report presenting a highly loaded transonic rotor which was designed, built, and tested as part of a two-stage counterrotating-compressor research program. The design conditions were chosen to explore the upper limits of loading and Mach number for the transonic unit. The complete rotor design procedure is presented as well as the recorded stall traces and techniques for obtaining the data.

Wind tunnel tests haved been made at low speed to various small-scale models of swept-back, swept-forward, and yawed wings. Tests covered changes in aspect ratio, taper ratio, and tip shape.

Report discussing methods, advantages, and disadvantages of locating rotating heat exchangers ahead of, within, and behind the main engine compressor. Heat rejection should occur at the compressor discharge for best engine performance. Results regarding turbojet-engine performance, turboprop-engine performance, and a comparison of engine performance with liquid- and air-cooling are provided.

Report presenting a flight-test program investigating a modification to an interceptor system. Results indicate that a significant improvement in the overall response characteristics of the system. The modification minimizes the interaction between the antenna and interceptor motions, which can have a serious influence on flight path stability during a lead-collision attack.

Report presenting an investigation to determine the static longitudinal stability and control characteristics of a tailless wing-body combination with a pointed wing of aspect ratio 2 and trailing-edge elevons. The effectiveness of inset tabs in reducing the elevon hinge moment was also determined. Results regarding the lift, drag, pitching moment, elevon hinge moment, tab hinge moment, elevon load, and center of pressure of elevon load are provided.

Memorandum presenting an investigation conducted at Mach number 1.90 to determine if Helmholtz resonators can be used in a typical ramjet configuration to damp pressure pulsations associated with shock oscillations. Only one of the two resonators was found to effectively damp pressure pulsations that occurred when the ram jet was operating in the vicinity of its peak pressure recovery. Neither was found to effectively damp pressure pulsations over the entire range of ramjet operating conditions.

From Summary: "An investigation is being conducted to determine the performance of the 12-stage axial-flow compressor of the XT-46 turbine-propeller engine. This compressor was designed to produce a pressure ratio of 9 at an adiabatic efficiency of 0.86. The design pressure ratios per stage were considerably greater than any employed in current aircraft gas-turbine engines using this type of compressor. The compressor performance was evaluated at two stations."

A full-scale turbojet engine was operated with pentaborane fuel continuously for 22 minutes at conditions simulating flight at a Mach number of 0.8 at an altitude of 50,000 feet. This period of operation is approximately three times longer than previously reported operation times. Although the specific fuel consumption was reduced from 1.3 with JP-4 fuel to 0.98 with pentaborane, a 13.2-percent reduction in net thrust was also encountered. A portion of this thrust loss is potentially recoverable with proper design of the engine components. The boron oxide deposition and erosion processes within the engine approached an equilibrium condition after approximately 22 minutes of operation with pentaborane.